/*---------------------------------------------------------------------------*
  Project:  TwlSDK - FS - libraries
  File:     fs_romfat_default.c

  Copyright 2007-2009 Nintendo.  All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law. They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Date:: 2009-06-04#$
  $Rev: 10698 $
  $Author: okubata_ryoma $

 *---------------------------------------------------------------------------*/


#include <nitro/fs.h>

#include <nitro/mi/memory.h>
#include <nitro/math/math.h>
#include <nitro/std.h>


#include "../include/util.h"
#include "../include/command.h"
#include "../include/rom.h"


#if defined(FS_IMPLEMENT)


/*---------------------------------------------------------------------------*/
/* Declarations */

// Synchronous system command blocking read structure
typedef struct FSiSyncReadParam
{
    FSArchive  *arc;
    u32         pos;
}
FSiSyncReadParam;

// Bit and alignment macros
#define	BIT_MASK(n)	((1 << (n)) - 1)


/*---------------------------------------------------------------------------*/
/* functions */

/*---------------------------------------------------------------------------*
  Name:         FSi_SeekAndReadSRL

  Description:  SRL access callback called from the ROM hash context

  Arguments:    userdata         Any user-defined data
                buffer            Transfer destination buffer
                offset            Transfer source ROM offset
                length           Transfer size

  Returns:      Size of the transmission
 *---------------------------------------------------------------------------*/
static int FSi_SeekAndReadSRL(void *userdata, void *buffer, u32 offset, u32 length)
{
    FSFile     *file = (FSFile*)userdata;
    if (file)
    {
        (void)FS_SeekFile(file, (int)offset, FS_SEEK_SET);
        (void)FS_ReadFile(file, buffer, (int)length);
    }
    return (int)length;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_TranslateCommand

  Description:  Calls a user procedure or the default process and returns the result.
                If a synchronous command returns an asynchronous response, wait for completion internally.
                If an asynchronous command returns an asynchronous response, return it as is.

  Arguments:    p_file           FSFile structure in which the command argument is stored
                Command: Command ID
                block		TRUE if blocking

  Returns:      Command processing result.
 *---------------------------------------------------------------------------*/
static FSResult FSi_TranslateCommand(FSFile *p_file, FSCommandType command, BOOL block);

/*---------------------------------------------------------------------------*
  Name:         FSi_ReadTable

  Description:  Execute synchronous Read inside synchronous-type command

  Arguments:    p                Synchronous read structure
                dst              Read data storage destination buffer
                len              Number of bytes to read

  Returns:      Result of synchronous read
 *---------------------------------------------------------------------------*/
static FSResult FSi_ReadTable(FSiSyncReadParam * p, void *dst, u32 len)
{
    FSResult                result;
    FSArchive       * const arc = p->arc;
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);


    if (context->load_mem)
    {
        MI_CpuCopy8((const void *)p->pos, dst, len);
        result = FS_RESULT_SUCCESS;
    }
    else
    {
        result = (*context->read_func) (arc, dst, p->pos, len);
        result = FSi_WaitForArchiveCompletion(arc->list, result);
    }
    p->pos += len;
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_SeekDirDirect

  Description:  Directly moves to beginning of specified directory

  Arguments:    file            Pointer that stores directory list
                id               Directory ID

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void FSi_SeekDirDirect(FSFile *file, u32 id)
{
    file->arg.seekdir.pos.arc = file->arc;
    file->arg.seekdir.pos.own_id = (u16)id;
    file->arg.seekdir.pos.index = 0;
    file->arg.seekdir.pos.pos = 0;
    (void)FSi_TranslateCommand(file, FS_COMMAND_SEEKDIR, TRUE);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_SeekDirDefault

  Description:  Default implementation of SEEKDIR command

  Arguments:    file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_SeekDirDefault(FSFile *file)
{
    FSResult                result;
    FSArchive       * const arc = file->arc;
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);

    const FSDirPos  * const arg = &file->arg.seekdir.pos;
    FSArchiveFNT            fnt;
    FSiSyncReadParam        param;
    param.arc = arc;
    param.pos = context->fnt + arg->own_id * sizeof(fnt);
    result = FSi_ReadTable(&param, &fnt, sizeof(fnt));
    if (result == FS_RESULT_SUCCESS)
    {
        file->prop.dir.pos = *arg;
        if ((arg->index == 0) && (arg->pos == 0))
        {
            file->prop.dir.pos.index = fnt.index;
            file->prop.dir.pos.pos = context->fnt + fnt.start;
        }
        file->prop.dir.parent = (u32)(fnt.parent & BIT_MASK(12));
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ReadDirDefault

  Description:  Default implementation of READDIR command

  Arguments:    file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_ReadDirDefault(FSFile *file)
{
    FSResult                result;
    FSDirEntry             *entry = file->arg.readdir.p_entry;
    u8                      len;

    FSiSyncReadParam        param;
    param.arc = file->arc;
    param.pos = file->prop.dir.pos.pos;

    result = FSi_ReadTable(&param, &len, sizeof(len));

    if (result == FS_RESULT_SUCCESS)
    {
        entry->name_len = (u32)(len & BIT_MASK(7));
        entry->is_directory = (u32)((len >> 7) & 1);
        if (entry->name_len == 0)
        {
            result = FS_RESULT_FAILURE;
        }
        else
        {
            if (!file->arg.readdir.skip_string)
            {
                result = FSi_ReadTable(&param, entry->name, entry->name_len);
                if (result != FS_RESULT_SUCCESS)
                {
                    return result;
                }
                entry->name[entry->name_len] = '\0';
            }
            else
            {
                param.pos += entry->name_len;
            }
            if (!entry->is_directory)
            {
                entry->file_id.arc = file->arc;
                entry->file_id.file_id = file->prop.dir.pos.index;
                ++file->prop.dir.pos.index;
            }
            else
            {
                u16     id;
                result = FSi_ReadTable(&param, &id, sizeof(id));
                if (result == FS_RESULT_SUCCESS)
                {
                    entry->dir_id.arc = file->arc;
                    entry->dir_id.own_id = (u16)(id & BIT_MASK(12));
                    entry->dir_id.index = 0;
                    entry->dir_id.pos = 0;
                }
            }
            if (result == FS_RESULT_SUCCESS)
            {
                file->prop.dir.pos.pos = param.pos;
            }
        }
    }

    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_FindPathDefault

  Description:  Default implementation of FINDPATH command
                (Uses SEEKDIR, READDIR  commands)

  Arguments:    p_dir           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_FindPathDefault(FSFile *p_dir)
{
    const char *path = p_dir->arg.findpath.path;
    const BOOL  is_dir = p_dir->arg.findpath.find_directory;

    // Path name search based on specified directory
    p_dir->arg.seekdir.pos = p_dir->arg.findpath.pos;
    (void)FSi_TranslateCommand(p_dir, FS_COMMAND_SEEKDIR, TRUE);
    for (; *path; path += (*path ? 1 : 0))
    {
        // Extract the entry name targeted for the search
        int     name_len = FSi_IncrementSjisPositionToSlash(path, 0);
        u32     is_directory = ((path[name_len] != '\0') || is_dir);
        // If an illegal directory such as "//" is detected, failure
        if (name_len == 0)
        {
            return FS_RESULT_INVALID_PARAMETER;
        }
        // Special directory specification
        else if (*path == '.')
        {
            // "." is the current directory
            if (name_len == 1)
            {
                path += 1;
                continue;
            }
            // ".." is the parent directory
            else if ((name_len == 2) & (path[1] == '.'))
            {
                if (p_dir->prop.dir.pos.own_id != 0)
                {
                    FSi_SeekDirDirect(p_dir, p_dir->prop.dir.parent);
                }
                path += 2;
                continue;
            }
        }
        else if (*path == '*')
        {
            // "*" specifies a wildcard (Ignore this with the archive procedure)
            break;
        }
        // If an entry name that is too long is detected, failure
        if (name_len > FS_FILE_NAME_MAX)
        {
            return FS_RESULT_NO_ENTRY;
        }
        // Enumerate entries and sequentially compare
        else
        {
            FSDirEntry etr;
            p_dir->arg.readdir.p_entry = &etr;
            p_dir->arg.readdir.skip_string = FALSE;
            for (;;)
            {
                // If corresponding entry did not exist even when the end is reached, failure
                if (FSi_TranslateCommand(p_dir, FS_COMMAND_READDIR, TRUE) != FS_RESULT_SUCCESS)
                {
                    return FS_RESULT_NO_ENTRY;
                }
                // If there is no match, ingore
                if ((is_directory == etr.is_directory) &&
                    (name_len == etr.name_len) && (FSi_StrNICmp(path, etr.name, (u32)name_len) == 0))
                {
                    // If directory, move to the top again
                    if (is_directory)
                    {
                        path += name_len;
                        p_dir->arg.seekdir.pos = etr.dir_id;
                        (void)FSi_TranslateCommand(p_dir, FS_COMMAND_SEEKDIR, TRUE);
                        break;
                    }
                    // If it is a file and expecting a directory, failure
                    else if (is_dir)
                    {
                        return FS_RESULT_NO_ENTRY;
                    }
                    // Discover the file
                    else
                    {
                        *p_dir->arg.findpath.result.file = etr.file_id;
                        return FS_RESULT_SUCCESS;
                    }
                }
            }
        }
    }
    // If file cannot be found, failure
    if (!is_dir)
    {
        return FS_RESULT_NO_ENTRY;
    }
    else
    {
        *p_dir->arg.findpath.result.dir = p_dir->prop.dir.pos;
        return FS_RESULT_SUCCESS;
    }
}

/*---------------------------------------------------------------------------*
  Name:         FSi_GetPathDefault

  Description:  Default implementation of GETPATH command
                (Uses SEEKDIR, READDIR  commands)

  Arguments:    file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_GetPathDefault(FSFile *file)
{
    FSResult            result;
    FSArchive   * const arc = file->arc;
    FSGetPathInfo      *p_info = &file->arg.getpath;
    FSDirEntry          entry;
    u32                 dir_id;
    u32                 file_id;

    enum
    { INVALID_ID = 0x10000 };

    FSFile              tmp[1];
    FS_InitFile(tmp);
    tmp->arc = arc;

    if (FS_IsDir(file))
    {
        dir_id = file->prop.dir.pos.own_id;
        file_id = INVALID_ID;
    }
    else
    {
        file_id = file->prop.file.own_id;
        {
            // Search for all directories from root
            u32     pos = 0;
            u32     num_dir = 0;
            dir_id = INVALID_ID;
            do
            {
                FSi_SeekDirDirect(tmp, pos);
                // Get total directory count first time
                if (!pos)
                {
                    num_dir = tmp->prop.dir.parent;
                }
                tmp->arg.readdir.p_entry = &entry;
                tmp->arg.readdir.skip_string = TRUE;
                while (FSi_TranslateCommand(tmp, FS_COMMAND_READDIR, TRUE) == FS_RESULT_SUCCESS)
                {
                    if (!entry.is_directory && (entry.file_id.file_id == file_id))
                    {
                        dir_id = tmp->prop.dir.pos.own_id;
                        break;
                    }
                }
            }
            while ((dir_id == INVALID_ID) && (++pos < num_dir));
        }
    }

    // FALSE if the corresponding directory cannot be found
    if (dir_id == INVALID_ID)
    {
        p_info->total_len = 0;
        result = FS_RESULT_NO_ENTRY;
    }
    else
    {
        // If path length not calculated, measure once this time
        {
            u32         id = dir_id;
            // First, add "archive name:/"
            const char *arcname = FS_GetArchiveName(arc);
            u32         len = (u32)STD_GetStringLength(arcname);
            len += 2;
            // Move to standard directory
            FSi_SeekDirDirect(tmp, id);
            // If necessary, add file name. (Already obtained)
            if (file_id != INVALID_ID)
            {
                len += entry.name_len;
            }
            // Trace back in order and add own name
            if (id != 0)
            {
                do
                {
                    // Move to parent and search self
                    FSi_SeekDirDirect(tmp, tmp->prop.dir.parent);
                    tmp->arg.readdir.p_entry = &entry;
                    tmp->arg.readdir.skip_string = TRUE;
                    while (FSi_TranslateCommand(tmp, FS_COMMAND_READDIR, TRUE) == FS_RESULT_SUCCESS)
                    {
                        if (entry.is_directory && (entry.dir_id.own_id == id))
                        {
                            len += entry.name_len + 1;
                            break;
                        }
                    }
                    id = tmp->prop.dir.pos.own_id;
                }
                while (id != 0);
            }
            // Save the currently calculated data
            p_info->total_len = (u16)(len + 1);
            p_info->dir_id = (u16)dir_id;
        }

        // Success if measuring path length is the objective
        if (!p_info->buf)
        {
            result = FS_RESULT_SUCCESS;
        }
        // Failure if buffer length is insufficient
        else if (p_info->buf_len < p_info->total_len)
        {
            result = FS_RESULT_NO_MORE_RESOURCE;
        }
        // Store the character string from the end
        else
        {
            u8         *dst = p_info->buf;
            u32         total = p_info->total_len;
            u32         pos = 0;
            u32         id = dir_id;
            // First, add "archive name:/"
            const char *arcname = FS_GetArchiveName(arc);
            u32         len = (u32)STD_GetStringLength(arcname);
            MI_CpuCopy8(arcname, dst + pos, len);
            pos += len;
            MI_CpuCopy8(":/", dst + pos, 2);
            pos += 2;
            // Move to standard directory
            FSi_SeekDirDirect(tmp, id);
            // If necessary, add file name.
            if (file_id != INVALID_ID)
            {
                tmp->arg.readdir.p_entry = &entry;
                tmp->arg.readdir.skip_string = FALSE;
                while (FSi_TranslateCommand(tmp, FS_COMMAND_READDIR, TRUE) == FS_RESULT_SUCCESS)
                {
                    if (!entry.is_directory && (entry.file_id.file_id == file_id))
                    {
                        break;
                    }
                }
                len = entry.name_len + 1;
                MI_CpuCopy8(entry.name, dst + total - len, len);
                total -= len;
            }
            else
            {
                // If directory, append only the end
                dst[total - 1] = '\0';
                total -= 1;
            }
            // Trace back in order and add own name
            if (id != 0)
            {
                do
                {
                    // Move to parent and search self
                    FSi_SeekDirDirect(tmp, tmp->prop.dir.parent);
                    tmp->arg.readdir.p_entry = &entry;
                    tmp->arg.readdir.skip_string = FALSE;
                    // Add "/"
                    dst[total - 1] = '/';
                    total -= 1;
                    // Search parent's children (previous self)
                    while (FSi_TranslateCommand(tmp, FS_COMMAND_READDIR, TRUE) == FS_RESULT_SUCCESS)
                    {
                        if (entry.is_directory && (entry.dir_id.own_id == id))
                        {
                            u32     len = entry.name_len;
                            MI_CpuCopy8(entry.name, dst + total - len, len);
                            total -= len;
                            break;
                        }
                    }
                    id = tmp->prop.dir.pos.own_id;
                }
                while (id != 0);
            }
            SDK_ASSERT(pos == total);
        }
        result = FS_RESULT_SUCCESS;
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_OpenFileFastDefault

  Description:  Default implementation of OPENFILEFAST command
                (Uses OPENFILEDIRECT command)

  Arguments:    p_file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_OpenFileFastDefault(FSFile *p_file)
{
    FSResult                result;
    FSArchive       * const p_arc = p_file->arc;
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(p_arc);
    const FSFileID         *p_id = &p_file->arg.openfilefast.id;
    const u32               index = p_id->file_id;

    {
        // Determine propriety of FAT accessing region
        u32     pos = (u32)(index * sizeof(FSArchiveFAT));
        if (pos >= context->fat_size)
        {
            result = FS_RESULT_NO_ENTRY;
        }
        else
        {
            // Obtain the image area of the specified file from FAT
            FSArchiveFAT fat;
            FSiSyncReadParam param;
            param.arc = p_arc;
            param.pos = context->fat + pos;
            result = FSi_ReadTable(&param, &fat, sizeof(fat));
            if (result == FS_RESULT_SUCCESS)
            {
                // Directly open
                p_file->arg.openfiledirect.top = fat.top;
                p_file->arg.openfiledirect.bottom = fat.bottom;
                p_file->arg.openfiledirect.index = index;
                result = FSi_TranslateCommand(p_file, FS_COMMAND_OPENFILEDIRECT, TRUE);
            }
        }
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_OpenFileDirectDefault

  Description:  Default implementation of OPENFILEDIRECT command

  Arguments:    p_file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_OpenFileDirectDefault(FSFile *p_file)
{
    p_file->prop.file.top = p_file->arg.openfiledirect.top;
    p_file->prop.file.pos = p_file->arg.openfiledirect.top;
    p_file->prop.file.bottom = p_file->arg.openfiledirect.bottom;
    p_file->prop.file.own_id = p_file->arg.openfiledirect.index;
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ReadFileDefault

  Description:  Default implementation of READFILE command

  Arguments:    file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_ReadFileDefault(FSFile *file)
{
    FSArchive       * const arc = file->arc;
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
    const u32               pos = file->prop.file.pos;
    const u32               len = file->arg.readfile.len;
    void            * const dst = file->arg.readfile.dst;
    file->prop.file.pos += len;
    return (*context->read_func) (arc, dst, pos, len);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_WriteFileDefault

  Description:  Default implementation of WRITEFILE command

  Arguments:    file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_WriteFileDefault(FSFile *file)
{
    FSArchive       * const arc = file->arc;
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
    const u32               pos = file->prop.file.pos;
    const u32               len = file->arg.writefile.len;
    const void      * const src = file->arg.writefile.src;
    file->prop.file.pos += len;
    return (*context->write_func) (arc, src, pos, len);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_IgnoredCommand

  Description:  Implements commands that do nothing by default

  Arguments:    file           Handle to process command

  Returns:      Command result value
 *---------------------------------------------------------------------------*/
static FSResult FSi_IgnoredCommand(FSFile *file)
{
    (void)file;
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_TranslateCommand

  Description:  Calls user procedure or default process
                If a synchronous command returns an asynchronous response, wait for completion internally.
                If an asynchronous command returns an asynchronous response, return it as is.

  Arguments:    file             FSFile structure that stores the argument
                Command: Command ID
                block            TRUE if blocking is necessary

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
FSResult FSi_TranslateCommand(FSFile *file, FSCommandType command, BOOL block)
{
    FSResult                result = FS_RESULT_PROC_DEFAULT;
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(file->arc);
    // Execute if it is a command that supports the procedure
    if ((context->proc_flag & (1 << command)) != 0)
    {
        result = (*context->proc) (file, command);
        switch (result)
        {
        case FS_RESULT_SUCCESS:
        case FS_RESULT_FAILURE:
        case FS_RESULT_UNSUPPORTED:
            break;
        case FS_RESULT_PROC_ASYNC:
            // Control asynchronous process handling in detail later.
            break;
        case FS_RESULT_PROC_UNKNOWN:
            // Unknown command, so switch to the default process from this time onward.
            result = FS_RESULT_PROC_DEFAULT;
            context->proc_flag &= ~(1 << command);
            break;
        }
    }
    // If not processed in the procedure, call default process
    if (result == FS_RESULT_PROC_DEFAULT)
    {
        static FSResult (*const (default_table[])) (FSFile *) =
        {
            FSi_ReadFileDefault,
            FSi_WriteFileDefault,
            FSi_SeekDirDefault,
            FSi_ReadDirDefault,
            FSi_FindPathDefault,
            FSi_GetPathDefault,
            FSi_OpenFileFastDefault,
            FSi_OpenFileDirectDefault,
            FSi_IgnoredCommand,
            FSi_IgnoredCommand,
            FSi_IgnoredCommand,
            FSi_IgnoredCommand,
            FSi_IgnoredCommand,
        };
        if (command < sizeof(default_table) / sizeof(*default_table))
        {
            result = (*default_table[command])(file);
        }
        else
        {
            result = FS_RESULT_UNSUPPORTED;
        }
    }
    // If necessary, block here
    if (block)
    {
        result = FSi_WaitForArchiveCompletion(file, result);
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_ReadFile

  Description:  The FS_COMMAND_READFILE command.

  Arguments:    arc: The calling archive
                file: The target file
                buffer: The memory to transfer to
                length           Transfer size

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_ReadFile(FSArchive *arc, FSFile *file, void *buffer, u32 *length)
{
    FSROMFATProperty   *prop = (FSROMFATProperty*)FS_GetFileUserData(file);
    const u32 pos = prop->file.pos;
    const u32 rest = (u32)(prop->file.bottom - pos);
    const u32 org = *length;
    if (*length > rest)
    {
        *length = rest;
    }
    file->arg.readfile.dst = buffer;
    file->arg.readfile.len_org = org;
    file->arg.readfile.len = *length;
    (void)arc;
    return FSi_TranslateCommand(file, FS_COMMAND_READFILE, FALSE);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_WriteFile

  Description:  The FS_COMMAND_WRITEFILE command.

  Arguments:    arc: The calling archive
                file: The target file
                buffer: The memory to transfer from
                length           Transfer size

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_WriteFile(FSArchive *arc, FSFile *file, const void *buffer, u32 *length)
{
    FSROMFATProperty   *prop = (FSROMFATProperty*)FS_GetFileUserData(file);
    const u32 pos = prop->file.pos;
    const u32 rest = (u32)(prop->file.bottom - pos);
    const u32 org = *length;
    if (*length > rest)
    {
        *length = rest;
    }
    file->arg.writefile.src = buffer;
    file->arg.writefile.len_org = org;
    file->arg.writefile.len = *length;
    (void)arc;
    return FSi_TranslateCommand(file, FS_COMMAND_WRITEFILE, FALSE);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_SeekDirectory

  Description:  FS_COMMAND_SEEKDIR command

  Arguments:    arc: The calling archive
                file: The target file
                id               Unique directory ID
                position         Indicate enumeration state

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_SeekDirectory(FSArchive *arc, FSFile *file, u32 id, u32 position)
{
    FSResult                result;
    FSROMFATCommandInfo    *arg = &file->arg;
    file->arc = arc;
    arg->seekdir.pos.arc = arc;
    arg->seekdir.pos.own_id = (u16)(id >> 0);
    arg->seekdir.pos.index = (u16)(id >> 16);
    arg->seekdir.pos.pos = position;
    result = FSi_TranslateCommand(file, FS_COMMAND_SEEKDIR, TRUE);
    if (result == FS_RESULT_SUCCESS)
    {
        FS_SetDirectoryHandle(file, arc, &file->prop);
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_ReadDirectory

  Description:  The FS_COMMAND_READDIR command.

  Arguments:    arc: The calling archive
                file: The target file
                info: Location to save information

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_ReadDirectory(FSArchive *arc, FSFile *file, FSDirectoryEntryInfo *info)
{
    FSResult                result;
    FSDirEntry              entry[1];
    FSROMFATCommandInfo    *arg = &file->arg;
    arg->readdir.p_entry = entry;
    arg->readdir.skip_string = FALSE;
    result = FSi_TranslateCommand(file, FS_COMMAND_READDIR, TRUE);
    if (result == FS_RESULT_SUCCESS)
    {
        info->shortname_length = 0;
        info->longname_length = entry->name_len;
        MI_CpuCopy8(entry->name, info->longname, info->longname_length);
        info->longname[info->longname_length] = '\0';
        if (entry->is_directory)
        {
            info->attributes = FS_ATTRIBUTE_IS_DIRECTORY;
            info->id = (u32)((entry->dir_id.own_id << 0) | (entry->dir_id.index << 16));
            info->filesize = 0;
        }
        else
        {
            info->attributes = 0;
            info->id = entry->file_id.file_id;
            info->filesize = 0;
            // If a valid file ID, get file size information from FAT
            {
                FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
                u32                     pos = (u32)(info->id * sizeof(FSArchiveFAT));
                if (pos < context->fat_size)
                {
                    FSArchiveFAT        fat;
                    FSiSyncReadParam    param;
                    param.arc = arc;
                    param.pos = context->fat + pos;
                    if (FSi_ReadTable(&param, &fat, sizeof(fat)) == FS_RESULT_SUCCESS)
                    {
                        info->filesize = (u32)(fat.bottom - fat.top);
                        // If running in NTR mode, record with a flag that the TWL dedicated region is not read
                        if (FSi_IsUnreadableRomOffset(arc, fat.top))
                        {
                            info->attributes |= FS_ATTRIBUTE_IS_OFFLINE;
                        }
                    }
                }
            }
        }
        info->mtime.year = 0;
        info->mtime.month = 0;
        info->mtime.day = 0;
        info->mtime.hour = 0;
        info->mtime.minute = 0;
        info->mtime.second = 0;
    }
    (void)arc;
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_FindPath

  Description:  FS_COMMAND_FINDPATH command

  Arguments:    arc: The calling archive
                base_dir_id  The base directory ID (0 for the root)
                path                Search path
                target_id           ID storage destination
                target_is_directory  Storage destination of whether this is a directory

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_FindPath(FSArchive *arc, u32 base_dir_id, const char *path, u32 *target_id, BOOL target_is_directory)
{
    FSResult        result;
    union
    {
        FSFileID    file;
        FSDirPos    dir;
    }
    id;
    FSFile  tmp[1];
    FS_InitFile(tmp);
    tmp->arc = arc;
    tmp->arg.findpath.pos.arc = arc;
    tmp->arg.findpath.pos.own_id = (u16)(base_dir_id >> 0);
    tmp->arg.findpath.pos.index = 0;
    tmp->arg.findpath.pos.pos = 0;
    tmp->arg.findpath.path = path;
    tmp->arg.findpath.find_directory = target_is_directory;
    if (target_is_directory)
    {
        tmp->arg.findpath.result.dir = &id.dir;
    }
    else
    {
        tmp->arg.findpath.result.file = &id.file;
    }
    result = FSi_TranslateCommand(tmp, FS_COMMAND_FINDPATH, TRUE);
    if (result == FS_RESULT_SUCCESS)
    {
        if (target_is_directory)
        {
            *target_id = id.dir.own_id;
        }
        else
        {
            *target_id = id.file.file_id;
        }
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_GetPath

  Description:  FS_COMMAND_GETPATH command.

  Arguments:    arc: The calling archive
                file: The target file
                is_directory        False, if file is a file, TRUE if it is a directory
                buffer      Path storage destination
                length            Buffer size

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_GetPath(FSArchive *arc, FSFile *file, BOOL is_directory, char *buffer, u32 *length)
{
    FSResult                result;
    FSROMFATCommandInfo    *arg = &file->arg;
    arg->getpath.total_len = 0;
    arg->getpath.dir_id = 0;
    arg->getpath.buf = (u8 *)buffer;
    arg->getpath.buf_len = *length;
    result = FSi_TranslateCommand(file, FS_COMMAND_GETPATH, TRUE);
    if (result == FS_RESULT_SUCCESS)
    {
        *length = arg->getpath.buf_len;
    }
    (void)arc;
    (void)is_directory;
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_OpenFileFast

  Description:  The FS_COMMAND_OPENFILEFAST command

  Arguments:    arc: The calling archive
                file: The target file
                id                  File ID
                mode: The access mode

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_OpenFileFast(FSArchive *arc, FSFile *file, u32 id, u32 mode)
{
    FSResult                result;
    FSROMFATCommandInfo    *arg = &file->arg;
    arg->openfilefast.id.arc = arc;
    arg->openfilefast.id.file_id = id;
    result = FSi_TranslateCommand(file, FS_COMMAND_OPENFILEFAST, TRUE);
    if (result == FS_RESULT_SUCCESS)
    {
        FS_SetFileHandle(file, arc, &file->prop);
    }
    (void)mode;
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_OpenFileDirect

  Description:  The FS_COMMAND_OPENFILEDIRECT command.

  Arguments:    arc: The calling archive
                file: The target file
                top                 File top offset
                bottom              File bottom offset
                id                  Storage destination for required file ID and results

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_OpenFileDirect(FSArchive *arc, FSFile *file, u32 top, u32 bottom, u32 *id)
{
    FSResult                result;
    FSROMFATCommandInfo    *arg = &file->arg;
    arg->openfiledirect.top = top;
    arg->openfiledirect.bottom = bottom;
    arg->openfiledirect.index = *id;
    result = FSi_TranslateCommand(file, FS_COMMAND_OPENFILEDIRECT, TRUE);
    if (result == FS_RESULT_SUCCESS)
    {
        FS_SetFileHandle(file, arc, &file->prop);
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_CloseFile

  Description:  The FS_COMMAND_CLOSEFILE command.

  Arguments:    arc: The calling archive
                file: The target file

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_CloseFile(FSArchive *arc, FSFile *file)
{
    FSResult            result;
    result = FSi_TranslateCommand(file, FS_COMMAND_CLOSEFILE, TRUE);
    FS_DetachHandle(file);
    (void)arc;
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_Activate

  Description:  The FS_COMMAND_ACTIVATE command.

  Arguments:    arc: The calling archive

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void FSi_ROMFAT_Activate(FSArchive* arc)
{
    FSFile  tmp[1];
    FS_InitFile(tmp);
    tmp->arc = arc;
    (void)FSi_TranslateCommand(tmp, FS_COMMAND_ACTIVATE, FALSE);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_Idle

  Description:  The FS_COMMAND_ACTIVATE command.

  Arguments:    arc: The calling archive

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void FSi_ROMFAT_Idle(FSArchive* arc)
{
    FSFile  tmp[1];
    FS_InitFile(tmp);
    tmp->arc = arc;
    (void)FSi_TranslateCommand(tmp, FS_COMMAND_IDLE, FALSE);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_Suspend

  Description:  The FS_COMMAND_SUSPEND command.

  Arguments:    arc: The calling archive

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void FSi_ROMFAT_Suspend(FSArchive* arc)
{
    FSFile  tmp[1];
    FS_InitFile(tmp);
    tmp->arc = arc;
    (void)FSi_TranslateCommand(tmp, FS_COMMAND_SUSPEND, FALSE);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_Resume

  Description:  The FS_COMMAND_RESUME command.

  Arguments:    arc: The calling archive

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void FSi_ROMFAT_Resume(FSArchive* arc)
{
    FSFile  tmp[1];
    FS_InitFile(tmp);
    tmp->arc = arc;
    (void)FSi_TranslateCommand(tmp, FS_COMMAND_RESUME, FALSE);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_OpenFile

  Description:  The FS_COMMAND_OPENFILE command.

  Arguments:    arc: The calling archive
                file: The target file
                baseid: The base directory (0 for the root)
                path :   File path
                mode: The access mode

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_OpenFile(FSArchive *arc, FSFile *file, u32 baseid, const char *path, u32 mode)
{
    FSResult    result;
    u32         fileid;
    result = FSi_ROMFAT_FindPath(arc, baseid, path, &fileid, FALSE);
    if (result == FS_RESULT_SUCCESS)
    {
        result = FSi_ROMFAT_OpenFileFast(arc, file, fileid, mode);
    }
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_SeekFile

  Description:  The FS_COMMAND_SEEKFILE command.

  Arguments:    arc: The calling archive
                file: The target file
                offset: The displacement and moved position
                from: The starting point to seek from

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_SeekFile(FSArchive *arc, FSFile *file, int *offset, FSSeekFileMode from)
{
    FSROMFATProperty   *prop = (FSROMFATProperty*)FS_GetFileUserData(file);
    int pos = *offset;
    switch (from)
    {
    case FS_SEEK_SET:
        pos += prop->file.top;
        break;
    case FS_SEEK_CUR:
    default:
        pos += prop->file.pos;
        break;
    case FS_SEEK_END:
        pos += prop->file.bottom;
        break;
    }
    // Considered seek processing outside of range to have failed
    if ((pos < (int)prop->file.top) || (pos > (int)prop->file.bottom))
    {
        return FS_RESULT_INVALID_PARAMETER;
    }
    else
    {
        prop->file.pos = (u32)pos;
        *offset = pos;
        (void)arc;
        return FS_RESULT_SUCCESS;
    }
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_GetFileLength

  Description:  The FS_COMMAND_GETFILELENGTH command.

  Arguments:    arc: The calling archive
                file: The target file
                length: Location to save the obtained size

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_GetFileLength(FSArchive *arc, FSFile *file, u32 *length)
{
    FSROMFATProperty   *prop = (FSROMFATProperty*)FS_GetFileUserData(file);
    *length = prop->file.bottom - prop->file.top;
    (void)arc;
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_GetFilePosition

  Description:  The FS_COMMAND_GETFILEPOSITION command.

  Arguments:    arc: The calling archive
                file: The target file
                length	 Storage destination of gotten position

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_GetFilePosition(FSArchive *arc, FSFile *file, u32 *position)
{
    FSROMFATProperty   *prop = (FSROMFATProperty*)FS_GetFileUserData(file);
    *position = prop->file.pos - prop->file.top;
    (void)arc;
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_Unmount

  Description:  The FS_COMMAND_UNMOUNT command

  Arguments:    arc: The calling archive

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void FSi_ROMFAT_Unmount(FSArchive *arc)
{
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
    if (FS_IsArchiveTableLoaded(arc))
    {
        OS_TWarning("memory may leak. preloaded-table of archive \"%s\" (0x%08X)",
                    FS_GetArchiveName(arc), context->load_mem);
    }
    context->base = 0;
    context->fat = 0;
    context->fat_size = 0;
    context->fnt = 0;
    context->fnt_size = 0;
    context->fat_bak = 0;
    context->fnt_bak = 0;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_GetArchiveCaps

  Description:  The FS_COMMAND_GETARCHIVECAPS command.

  Arguments:    arc: The calling archive
                caps: Location to save the device capability flag

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_GetArchiveCaps(FSArchive *arc, u32 *caps)
{
    (void)arc;
    *caps = 0;
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_OpenDirectory

  Description:  The FS_COMMAND_OPENDIRECTORY command.

  Arguments:    arc: The calling archive
                file: The target file
                baseid: The base directory ID (0 for the root)
                path: The path
                mode: The access mode

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_OpenDirectory(FSArchive *arc, FSFile *file, u32 baseid, const char *path, u32 mode)
{
    FSResult    result = FS_RESULT_ERROR;
    u32         id = 0;
    result = FSi_ROMFAT_FindPath(arc, baseid, path, &id, TRUE);
    if (result == FS_RESULT_SUCCESS)
    {
        result = FSi_ROMFAT_SeekDirectory(arc, file, id, 0);
    }
    (void)mode;
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_CloseDirectory

  Description:  The FS_COMMAND_CLOSEDIRECTORY command.

  Arguments:    arc: The calling archive
                file: The target file

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_CloseDirectory(FSArchive *arc, FSFile *file)
{
    FS_DetachHandle(file);
    (void)arc;
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_GetPathInfo

  Description:  The FS_COMMAND_GETPATHINFO command.

  Arguments:    arc: The calling archive
                baseid: The base directory ID (0 for the root)
                path: The path
                info: Location to save file information

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_GetPathInfo(FSArchive *arc, u32 baseid, const char *path, FSPathInfo *info)
{
    FSResult    result = FS_RESULT_ERROR;
    u32         id = 0;
    MI_CpuFill8(info, 0x00, sizeof(*info));
    // The ratio is quite poor, so it is better to call the function separately
    if (FSi_ROMFAT_FindPath(arc, baseid, path, &id, TRUE) == FS_RESULT_SUCCESS)
    {
        info->attributes = FS_ATTRIBUTE_IS_DIRECTORY;
        info->id = id;
        result = FS_RESULT_SUCCESS;
    }
    else if (FSi_ROMFAT_FindPath(arc, baseid, path, &id, FALSE) == FS_RESULT_SUCCESS)
    {
        info->attributes = 0;
        info->id = id;
        info->filesize = 0;
        // If a valid file ID, get file size information from FAT
        {
            FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
            u32                     pos = (u32)(id * sizeof(FSArchiveFAT));
            if (pos < context->fat_size)
            {
                FSArchiveFAT        fat;
                FSiSyncReadParam    param;
                param.arc = arc;
                param.pos = context->fat + pos;
                if (FSi_ReadTable(&param, &fat, sizeof(fat)) == FS_RESULT_SUCCESS)
                {
                    info->filesize = (u32)(fat.bottom - fat.top);
                    // If running in NTR mode, record with a flag that the TWL dedicated region is not read
                    if (FSi_IsUnreadableRomOffset(arc, fat.top))
                    {
                        info->attributes |= FS_ATTRIBUTE_IS_OFFLINE;
                    }
                }
            }
        }
        result = FS_RESULT_SUCCESS;
    }
    // The NitroROM format archive prohibits writing by default
    info->attributes |= FS_ATTRIBUTE_IS_PROTECTED;
    return result;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ROMFAT_GetPathInfo

  Description:  The FATFS_COMMAND_GETARCHIVERESOURCE command.

  Arguments:    arc: The calling archive
                resource            Storage destination of resource information

  Returns:      The processing result for the command.
 *---------------------------------------------------------------------------*/
static FSResult FSi_ROMFAT_GetArchiveResource(FSArchive *arc, FSArchiveResource *resource)
{
    const CARDRomHeader    *header = (const CARDRomHeader *)CARD_GetRomHeader();
    resource->bytesPerSector = 0;
    resource->sectorsPerCluster = 0;
    resource->totalClusters = 0;
    resource->availableClusters = 0;
    resource->totalSize = header->rom_size;
    resource->availableSize = 0;
    resource->maxFileHandles = 0x7FFFFFFF;
    resource->currentFileHandles = 0;
    resource->maxDirectoryHandles = 0x7FFFFFFF;
    resource->currentDirectoryHandles = 0;
    (void)arc;
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ReadSRLCallback

  Description:  SRL file read callback

  Arguments:    p_arc            FSArchive structure
                dst        Transfer destination
                src        Transfer source
                len        Transfer size

  Returns:      Read process results
 *---------------------------------------------------------------------------*/
static FSResult FSi_ReadSRLCallback(FSArchive *arc, void *buffer, u32 offset, u32 length)
{
    CARDRomHashContext *hash = (CARDRomHashContext*)FS_GetArchiveBase(arc);
    CARD_ReadRomHashImage(hash, buffer, offset, length);
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_SRLArchiveProc

  Description:  SRL file archive procedure

  Arguments:    file           FSFile structure that stores command information
                cmd:              Command type.

  Returns:      Command processing result
 *---------------------------------------------------------------------------*/
static FSResult FSi_SRLArchiveProc(FSFile *file, FSCommandType cmd)
{
    (void)file;
    switch (cmd)
    {
    case FS_COMMAND_WRITEFILE:
        return FS_RESULT_UNSUPPORTED;
    default:
        return FS_RESULT_PROC_UNKNOWN;
    }
}

/*---------------------------------------------------------------------------*
  Name:         FSi_MountSRLFile

  Description:  Mount the ROM file system that is included in the SRL file

  Arguments:    arc              FSArchive structure used in mounting
                                 Names must have been registered
                file             File targeted for mounting and that is already open
                                 Do not destroy this structure while mounting
                hash             Hash context structure

  Returns:      TRUE if the process is successful
 *---------------------------------------------------------------------------*/
BOOL FSi_MountSRLFile(FSArchive *arc, FSFile *file, CARDRomHashContext *hash)
{
    BOOL                    retval = FALSE;
    static CARDRomHeaderTWL header[1] ATTRIBUTE_ALIGN(32);
    if (file &&
        (FS_SeekFileToBegin(file) &&
        (FS_ReadFile(file, header, sizeof(header)) == sizeof(header))))
    {
        // For security, NAND applications require a hash table
        // When a ROM called NITRO compatible mode but will use the file system appears in the future, study usage policy at that time
        // 
        if ((((const u8 *)header)[0x1C] & 0x01) != 0)
        {
            FSResult (*proc)(FSFile*, FSCommandType) = FSi_SRLArchiveProc;
            FSResult (*read)(FSArchive*, void*, u32, u32) = FSi_ReadSRLCallback;
            FSResult (*write)(FSArchive*, const void*, u32, u32) = NULL;
            FS_SetArchiveProc(arc, proc, FS_ARCHIVE_PROC_WRITEFILE);
            // Access change is created in the order of arc -> hash -> files
            if (FS_LoadArchive(arc, (u32)hash,
                               header->ntr.fat.offset, header->ntr.fat.length,
                               header->ntr.fnt.offset, header->ntr.fnt.length,
                               read, write))
            {
                // If it was content that differed from the ROM header of the system work region, the buffer allocated in advance by the CARDi_InitRom function is wasted
                // 
                extern u8  *CARDiHashBufferAddress;
                extern u32  CARDiHashBufferLength;
                u32         len = CARD_CalcRomHashBufferLength(header);
                if (len > CARDiHashBufferLength)
                {
                    u8     *lo = (u8 *)MATH_ROUNDUP((u32)OS_GetMainArenaLo(), 32);
                    u8     *hi = (u8 *)MATH_ROUNDDOWN((u32)OS_GetMainArenaHi(), 32);
                    if (&lo[len] > hi)
                    {
                        OS_TPanic("cannot allocate memory for ROM-hash from ARENA");
                    }
                    else
                    {
                        OS_SetMainArenaLo(&lo[len]);
                        CARDiHashBufferAddress = lo;
                        CARDiHashBufferLength = len;
                    }
                }
                CARD_InitRomHashContext(hash, header,
                                        CARDiHashBufferAddress, CARDiHashBufferLength,
                                        FSi_SeekAndReadSRL, NULL, file);
                // Destroy the pointer so that there is no competition for use of the same buffer
                CARDiHashBufferAddress = NULL;
                CARDiHashBufferLength = 0;
                retval = TRUE;
            }
        }
    }
    return retval;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_ReadMemCallback

  Description:  Default memory read callback

  Arguments:    p_arc:          Archive on which to operate
                dst:              Storage destination of the memory to read
                pos             Read position
                size             Size to read

  Returns:      Always FS_RESULT_SUCCESS
 *---------------------------------------------------------------------------*/
static FSResult FSi_ReadMemCallback(FSArchive *p_arc, void *dst, u32 pos, u32 size)
{
    MI_CpuCopy8((const void *)FS_GetArchiveOffset(p_arc, pos), dst, size);
    return FS_RESULT_SUCCESS;
}

/*---------------------------------------------------------------------------*
  Name:         FSi_WriteMemCallback

  Description:  Default memory write callback

  Arguments:    p_arc:          Archive on which to operate
                dst:              Reference destination of the memory to write
                pos:              Write location
                size             Size to write

  Returns:      Always FS_RESULT_SUCCESS
 *---------------------------------------------------------------------------*/
static FSResult FSi_WriteMemCallback(FSArchive *p_arc, const void *src, u32 pos, u32 size)
{
    MI_CpuCopy8(src, (void *)FS_GetArchiveOffset(p_arc, pos), size);
    return FS_RESULT_SUCCESS;
}

static const FSArchiveInterface FSiArchiveProcInterface =
{
    // Commands that are compatible with old specifications
    FSi_ROMFAT_ReadFile,
    FSi_ROMFAT_WriteFile,
    FSi_ROMFAT_SeekDirectory,
    FSi_ROMFAT_ReadDirectory,
    FSi_ROMFAT_FindPath,
    FSi_ROMFAT_GetPath,
    FSi_ROMFAT_OpenFileFast,
    FSi_ROMFAT_OpenFileDirect,
    FSi_ROMFAT_CloseFile,
    FSi_ROMFAT_Activate,
    FSi_ROMFAT_Idle,
    FSi_ROMFAT_Suspend,
    FSi_ROMFAT_Resume,
    // Items that are compatible with old specifications but were not commands
    FSi_ROMFAT_OpenFile,
    FSi_ROMFAT_SeekFile,
    FSi_ROMFAT_GetFileLength,
    FSi_ROMFAT_GetFilePosition,
    // Command extended by the new specifications (UNSUPPORTED if NULL)
    NULL,               // Mount
    FSi_ROMFAT_Unmount,
    FSi_ROMFAT_GetArchiveCaps,
    NULL,               // CreateFile
    NULL,               // DeleteFile
    NULL,               // RenameFile
    FSi_ROMFAT_GetPathInfo,
    NULL,               // SetFileInfo
    NULL,               // CreateDirectory
    NULL,               // DeleteDirectory
    NULL,               // RenameDirectory
    FSi_ROMFAT_GetArchiveResource,
    NULL,               // 29UL
    NULL,               // FlushFile
    NULL,               // SetFileLength
    FSi_ROMFAT_OpenDirectory,
    FSi_ROMFAT_CloseDirectory,
};

/*---------------------------------------------------------------------------*
  Name:         FS_LoadArchive

  Description:  Loads the archive into the file system.
                Its name must already be registered on the archive list.

  Arguments:    arc            Archive to load
                base             Any u32 value that can be uniquely used.
                fat              Starting offset of the FAT table
                fat_size         Size of FAT table
                fat              Starting offset of the FNT table
                fat_size         Size of FNT table
                read_func        Read access callback.
                write_func       Write access callback

  Returns:      TRUE if archive is loaded correctly
 *---------------------------------------------------------------------------*/
BOOL FS_LoadArchive(FSArchive *arc, u32 base,
                    u32 fat, u32 fat_size,
                    u32 fnt, u32 fnt_size,
                    FS_ARCHIVE_READ_FUNC read_func, FS_ARCHIVE_WRITE_FUNC write_func)
{
    BOOL    retval = FALSE;
    SDK_ASSERT(FS_IsAvailable());
    SDK_NULL_ASSERT(arc);
    SDK_ASSERT(!FS_IsArchiveLoaded(arc));

    // Initialize information for archive
    {
        FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)arc->reserved2;
        context->base = base;
        context->fat_size = fat_size;
        context->fat = fat;
        context->fat_bak = fat;
        context->fnt_size = fnt_size;
        context->fnt = fnt;
        context->fnt_bak = fnt;
        context->read_func = read_func ? read_func : FSi_ReadMemCallback;
        context->write_func = write_func ? write_func : FSi_WriteMemCallback;
        context->load_mem = NULL;
        return FS_MountArchive(arc, context, &FSiArchiveProcInterface, 0);
    }
    return retval;
}

/*---------------------------------------------------------------------------*
  Name:         FS_UnloadArchive

  Description:  Unload the archive from the file system.
                Block until all currently running tasks are completed.

  Arguments:    arc            Archive to unload

  Returns:      TRUE if archive is unloaded correctly.
 *---------------------------------------------------------------------------*/
BOOL FS_UnloadArchive(FSArchive *arc)
{
    return FS_UnmountArchive(arc);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_GetFileLengthIfProc

  Description:  If the specified file is an archive procedure, gets the size.

  Arguments:    file        File handle
                length			Storage destination of the size

  Returns:      If the specified file is an archive procedure, returns its size
 *---------------------------------------------------------------------------*/
BOOL FSi_GetFileLengthIfProc(FSFile *file, u32 *length)
{
    return (file->arc->vtbl == &FSiArchiveProcInterface) &&
           (FSi_ROMFAT_GetFileLength(file->arc, file, length) == FS_RESULT_SUCCESS);
}

/*---------------------------------------------------------------------------*
  Name:         FSi_GetFilePositionIfProc

  Description:  If the specified file is an archive procedure, gets the current position

  Arguments:    file        File handle
                length			Storage destination of the size

  Returns:      If the specified file is an archive procedure, returns its current position
 *---------------------------------------------------------------------------*/
BOOL FSi_GetFilePositionIfProc(FSFile *file, u32 *length)
{
    return (file->arc->vtbl == &FSiArchiveProcInterface) &&
           (FSi_ROMFAT_GetFilePosition(file->arc, file, length) == FS_RESULT_SUCCESS);
}

/*---------------------------------------------------------------------------*
  Name:         FS_SetArchiveProc

  Description:  Sets the archive's user procedure.
                If proc == NULL or flags = 0,
                Merely invalidates the user procedure.

  Arguments:    arc     Archive for which to set the user procedure.
                proc             User procedure.
                flags            Bit collection of commands that hook to procedures.

  Returns:      Always returns the total table size.
 *---------------------------------------------------------------------------*/
void FS_SetArchiveProc(FSArchive *arc, FS_ARCHIVE_PROC_FUNC proc, u32 flags)
{
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)arc->reserved2;
    if (!flags)
    {
        proc = NULL;
    }
    else if (!proc)
    {
        flags = 0;
    }
    context->proc = proc;
    context->proc_flag = flags;
}

/*---------------------------------------------------------------------------*
  Name:         FS_LoadArchiveTables

  Description:  Preloads archive FAT + FNT in memory.
                Only if within specified size, execute the load and return the required size.

  Arguments:    p_arc            Archive that will preload table.
                p_mem            Storage destination buffer for table data
                max_size         p_mem size

  Returns:      Always returns the total table size.
 *---------------------------------------------------------------------------*/
u32 FS_LoadArchiveTables(FSArchive *p_arc, void *p_mem, u32 max_size)
{
    SDK_ASSERT(FS_IsAvailable());
    SDK_NULL_ASSERT(p_arc);

    // If this is a table that has already been loaded, unload it
    if ((p_mem != NULL) && FS_IsArchiveTableLoaded(p_arc))
    {
        (void)FS_UnloadArchiveTables(p_arc);
    }

    {
        FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(p_arc);
        // The preload size is 32-byte aligned.
        u32     total_size = (u32)((context->fat_size + context->fnt_size + 32 + 31) & ~31);
        if (total_size <= max_size)
        {
            // If the size is sufficient, load into memory.
            u8     *p_cache = (u8 *)(((u32)p_mem + 31) & ~31);
            FSFile  tmp;
            FS_InitFile(&tmp);
            // Sometimes the table cannot be read.
            // * In that case, nothing is done because the table could not be accessed originally.
            if (FS_OpenFileDirect(&tmp, p_arc, context->fat, context->fat + context->fat_size, (u32)~0))
            {
                if (FS_ReadFile(&tmp, p_cache, (s32)context->fat_size) < 0)
                {
                    MI_CpuFill8(p_cache, 0x00, context->fat_size);
                }
                (void)FS_CloseFile(&tmp);
            }
            context->fat = (u32)p_cache;
            p_cache += context->fat_size;
            if (FS_OpenFileDirect(&tmp, p_arc, context->fnt, context->fnt + context->fnt_size, (u32)~0))
            {
                if (FS_ReadFile(&tmp, p_cache, (s32)context->fnt_size) < 0)
                {
                    MI_CpuFill8(p_cache, 0x00, context->fnt_size);
                }
                (void)FS_CloseFile(&tmp);
            }
            context->fnt = (u32)p_cache;
            // Thereafter, preload memory will be used with table reads.
            context->load_mem = p_mem;
            p_arc->flag |= FS_ARCHIVE_FLAG_TABLE_LOAD;
        }
        return total_size;
    }
}

/*---------------------------------------------------------------------------*
  Name:         FS_UnloadArchiveTables

  Description:  Deallocates the archive's preloaded memory.

  Arguments:    arc            Archive with preloaded memory to release.

  Returns:      Buffer given by the user as preloaded memory.
 *---------------------------------------------------------------------------*/
void   *FS_UnloadArchiveTables(FSArchive *arc)
{
    void   *retval = NULL;

    SDK_ASSERT(FS_IsAvailable());
    SDK_NULL_ASSERT(arc);

    if (FS_IsArchiveLoaded(arc))
    {
        FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
        BOOL    bak_stat = FS_SuspendArchive(arc);
        if (FS_IsArchiveTableLoaded(arc))
        {
            arc->flag &= ~FS_ARCHIVE_FLAG_TABLE_LOAD;
            retval = context->load_mem;
            context->fat = context->fat_bak;
            context->fnt = context->fnt_bak;
            context->load_mem = NULL;
        }
        if (bak_stat)
        {
            (void)FS_ResumeArchive(arc);
        }
    }
    return retval;
}

/*---------------------------------------------------------------------------*
  Name:         FS_GetArchiveBase

  Description:  Gets ROMFAT-type archive base offset

  Arguments:    arc              ROMFAT-type archive

  Returns:      ROMFAT-type archive base offset
 *---------------------------------------------------------------------------*/
u32 FS_GetArchiveBase(const struct FSArchive *arc)
{
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
    return context->base;
}

/*---------------------------------------------------------------------------*
  Name:         FS_GetArchiveFAT

  Description:  Gets ROMFAT-type archive FAT offset

  Arguments:    arc              ROMFAT-type archive

  Returns:      ROMFAT-type archive FAT offset
 *---------------------------------------------------------------------------*/
u32 FS_GetArchiveFAT(const struct FSArchive *arc)
{
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
    return context->fat;
}

/*---------------------------------------------------------------------------*
  Name:         FS_GetArchiveFNT

  Description:  Gets ROMFAT-type archive FNT offset

  Arguments:    arc              ROMFAT-type archive

  Returns:      ROMFAT-type archive FNT offset
 *---------------------------------------------------------------------------*/
u32 FS_GetArchiveFNT(const struct FSArchive *arc)
{
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
    return context->fnt;
}

/* Obtain specified position offset from the archive's base */
/*---------------------------------------------------------------------------*
  Name:         FS_GetArchiveOffset

  Description:  Gets specified position offset from the ROMFAT-type archive's base

  Arguments:    arc              ROMFAT-type archive

  Returns:      Specified position offset with the archive base added
 *---------------------------------------------------------------------------*/
u32 FS_GetArchiveOffset(const struct FSArchive *arc, u32 pos)
{
    FSROMFATArchiveContext *context = (FSROMFATArchiveContext*)FS_GetArchiveUserData(arc);
    return context->base + pos;
}

/*---------------------------------------------------------------------------*
  Name:         FS_IsArchiveTableLoaded

  Description:  Determines whether the ROMFAT-type archive has finished preloading the table.

  Arguments:    arc              ROMFAT-type archive

  Returns:      TRUE if the table has been preloaded
 *---------------------------------------------------------------------------*/
BOOL FS_IsArchiveTableLoaded(volatile const struct FSArchive *arc)
{
    return ((arc->flag & FS_ARCHIVE_FLAG_TABLE_LOAD) != 0);
}

/*---------------------------------------------------------------------------*
  Name:         FS_GetFileImageTop

  Description:  Gets the top offset of the file opened from the ROMFAT-type archive
                

  Arguments:    file        File handle

  Returns:      File top offset on the archive
 *---------------------------------------------------------------------------*/
u32 FS_GetFileImageTop(const struct FSFile *file)
{
    return file->prop.file.top;
}

/*---------------------------------------------------------------------------*
  Name:         FS_GetFileImageBottom

  Description:  Gets the bottom offset of the file opened from the ROMFAT-type archive
                

  Arguments:    file        File handle

  Returns:      File bottom offset on the archive
 *---------------------------------------------------------------------------*/
u32 FS_GetFileImageBottom(const struct FSFile *file)
{
    return file->prop.file.bottom;
}


#endif /* FS_IMPLEMENT */